U.S. patent application number 10/435028 was filed with the patent office on 2003-10-30 for process and apparatus for producing compost.
This patent application is currently assigned to Sapporo Breweries Limited. Invention is credited to Kobayashi, Fujio, Kurihara, Toshio, Nakakita, Yasukazu, Yagihashi, Shinji, Yamashita, Shinji.
Application Number | 20030200780 10/435028 |
Document ID | / |
Family ID | 26483923 |
Filed Date | 2003-10-30 |
United States Patent
Application |
20030200780 |
Kind Code |
A1 |
Yagihashi, Shinji ; et
al. |
October 30, 2003 |
Process and apparatus for producing compost
Abstract
The present invention relates to a process for producing
compost, characterized in that when the compost is produced by
inoculating aerobic composting seed bacteria to an organic waste
material, the process comprises: supplying oxygen while the waste
material is stirred, and supplying water so that the water content
of the waste material is 60.+-.5%, and to a process for producing
compost, characterized in that when the compost is produced by
inoculating aerobic composting seed bacteria to an organic waste
material, the process comprises, after begining of the
fermentation, adding sugars to the waste material in a divisional
manner before a main fermentation is transferred to the
amine/ammonium metabolic system. Further, according to the present
invention, an apparatus for producing compost is provided. The
apparatus comprises: a fermentation vessel having an oxygen
supplying means, a water distributing means, and a stirring means;
and a control means for detecting or determining the moisture
content of an organic waste material contained in the fermentation
vessel to control, on the basis of the detected or determined
result, the amount of water to be distributed by the water
distributing means. According to the present invention, when
organic waste materials disposed from food processing factories and
the like is processed to produce compost of high quality, formation
of ammonium and amines mainly causing unpleasant odors or
generation of lower fatty acid which is a factor for a growth
inhibition of plants can be suppressed, and the compost can be
produced in stable, and within a short period of time.
Inventors: |
Yagihashi, Shinji;
(Shizuoka-ken, JP) ; Kurihara, Toshio;
(Shizuoka-ken, JP) ; Yamashita, Shinji;
(Shizuoka-ken, JP) ; Kobayashi, Fujio;
(Shizuoka-ken, JP) ; Nakakita, Yasukazu;
(Shizuoka-ken, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Sapporo Breweries Limited
Tokyo
JP
|
Family ID: |
26483923 |
Appl. No.: |
10/435028 |
Filed: |
May 12, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10435028 |
May 12, 2003 |
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09716948 |
Nov 22, 2000 |
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6607909 |
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09716948 |
Nov 22, 2000 |
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09147610 |
Feb 1, 1999 |
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6217628 |
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09147610 |
Feb 1, 1999 |
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PCT/JP98/02376 |
May 29, 1998 |
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Current U.S.
Class: |
71/9 |
Current CPC
Class: |
C05F 17/00 20130101;
Y02W 30/40 20150501; Y02P 20/145 20151101; C05F 17/90 20200101;
C05F 17/20 20200101; C05F 17/70 20200101 |
Class at
Publication: |
71/9 |
International
Class: |
C05F 011/08 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 1997 |
JP |
9-156090 |
Jul 10, 1997 |
JP |
9-199179 |
Claims
1. A process for producing compost characterized in that when the
compost is produced by inoculating aerobic composting seed bacteria
to an organic waste material, said process comprises: supplying
oxygen while the waste material is stirred; and supplying water so
that the water content of the waste material is 60.+-.5%.
2. A process for producing compost, characterized in that when the
compost is produced by inoculating aerobic composting seed bacteria
to an organic waste material, said process comprises, after
begining of the fermentation, adding sugars to the waste material
in a divisional manner before a main fermentation is transferred to
the amine/ammonium metabolic system.
3. An apparatus for producing compost, comprising: a fermentation
vessel having an oxygen supply means, a water distributing means,
and a stirring means; and a control means for detecting or
determining a moisture content of an organic waste material
contained in the fermentation vessel to control, on the basis of
the detected or determined result, the distribution amount
distributed by the water distributing means.
Description
TECHNICAL FIELD
[0001] The present invention relates to a process for producing
compost and an apparatus therefor. More specifically, the present
invention is directed to a process for producing compost with high
quality having less unpleasantly odors within a short period of
time by processing organic waste materials disposed from food
processing factories and the like, and to an apparatus for
producing the same.
TECHNICAL BACKGROUND
[0002] Conventionally, composting has been conducted to realize
effective utilization of waste materials in food industry, food
processing industry, livestock industry, and the like where organic
waste materials are most likely to be produced. In such
municipalities that deal with urban garbage, composting has also
been conducted for the purpose of volume reduction or conversion to
stable substances. In particular, many organic waste materials
disposed from food processing factories and the like are likely to
have high water content at the time of being disposed from these
factories. Therefore, if it is left alone during summer, a variety
of bacteria may grow, putrefaction may begin, and unpleasant odors
that mainly come from putrefaction odors may occur. Then, there
arises a problem in view of the environmental protection.
[0003] Further, since the waste materials have in general high
moisture content when composted, the anaerobic environment may be
partially generated within a fermentation vessel. Then, the
fermentation operation may be conducted under the mixture condition
of anaerobic bacteria and aerobic bacteria, so that the
fermentation efficiency is low. Typically, several months are
required until protein, fat, or the like are decomposed and
stabilized as compost.
[0004] Still further, since the fermentation efficiency is low as
described above, unpleasant odors caused by amines, ammonium, or
the like as major component are always carried while compost is
produced. In addition, the sufficient fermentation operation may
not be possibly conducted, the obtained product may be fermented
again when it is used as compost, and then unpleasant odors may
possibly occur. Furthermore, it cannot be avoided to accumulate,
during composting, lower fatty acid serving as a factor for the
growth inhibition of plants.
[0005] As means for suppressing the above, some processes using
various microorganisms have been attempted In fact, however, any
satisfactory effects have not been obtained
[0006] Moreover, the thus obtained compost may be of fine powders
like soil, in which decomposed fibers may remain large, so that
inconvenience in handling may be arisen for packing,
transportation, storage, dispersion, and the like. In particular,
such fine powder can be easily scurried when it is dispersed, and
thus such compost must be dispersed selectively on unwindy
days.
[0007] A first object of the present invention is to overcome the
above-described conventional problems, and to establish a process
for producing compost in a stable manner and in a short period of
time by conducting the steps of fermentation and composting for
organic waste materials under the aerobic condition, reducing the
occurrence period of ammonium and amines causing unpleasant odors,
preventing the reoccurrence of such unpleasant odors, and
inhibiting occurrence and accumulation of lower fatty acid (e.g.,
isobutyric acid, butyric acid, isovaleric acid, and acetic acid)
which are inhibitor of the growth of plants.
[0008] Also, in order to improve workability for dispersing the
compost, the one having a predetermined size and weight will be
necessary.
[0009] According to the study of the inventors of the present
invention, it has been discovered that for the purpose of realizing
and sustaining the aerobic fermentation state effective for
composting, the oxygen concentration in an organic waste material
(hereinafter, sometimes referred to as "material") must be
constantly kept at a predetermined value or more, and an
appropriate water content in the material must be kept. The present
inventors have made intensive investigation and have then
discovered that uniform and excellent fermentation with the aerobic
bacteria can be achieved by stirring the whole material in a
fermentation tank to uniformly sustain the fermentation, supplying
oxygen over the entire material, and supplying water to keep the
water content of the material at 60.+-.5%.
[0010] Further, when the aerobic fermentation is conducted using
spent grains as material, during its primary fermentation period,
small amount of saccharide (or sugar) contained in the spent grains
is initially decomposed, sugars obtained by decomposing
hemicellulose or cellulose are then used as an energy source for
the growth of microorganisms. On the other hand, the present
inventors assume that, when cellulose or the like is slowly
decomposed, the aerobic bacteria obtain energy for the growth
through the metabolic pathway in which it is decomposed from
protein to amines/ammonium through amino acid (hereinafter,
referred to as "amine/ammonium metabolic system"), whereby
unpleasant odors may be generated. Therefore, it is conceivable
that the metabolic system from protein to amino acid is replaced
with the metabolic growth system using sugar as an energy source,
so that occurrence of such unpleasant odors at the fermentation may
be prevented.
[0011] This assumption is supported by existence of the report that
when sugars such as molasses are added at a time at the beginning
of fermentation to compost organic waste materials, such unpleasant
odors can be more prevented from occurring in comparison with the
case where no sugar is added. According to the study of the
inventors of the present invention, however, the fermentation is
allowed to slowly proceed under this method of adding at a time
(batch addition method), so that not only sugar metabolism but also
the fermentation in the protein-amino acid decomposition metabolic
system may be possibly activated, and occurrence of such unpleasant
odors may not be sufficiently prevented.
[0012] Accordingly, in order to solve the above described problems,
a second object of the present invention is to control the
fermentation so that the subject of the aerobic fermentation may be
always fermented through the sugar decomposition metabolism, and
therefore to provide a process for adding sugars in a divisional
manner at a predetermined timing so that the aerobic fermentation
may not transfer to the fermentation based on the protein-amino
acid decomposition metabolism, so that the fermentation based on
the metabolic growth system using saccharides as an energy source
can be conducted, for greatly inhibiting occurrence of the amines
and ammonium causing such unpleasant odors at the fermentation, and
for producing compost with high quality.
DISCLOSURE OF THE INVENTION
[0013] Therefore, the present invention relates to a process for
producing compost, characterized in that when the compost is
produced by inoculating aerobic composting seed bacteria to an
organic waste material, the process comprises: supplying oxygen
while the waste material is stirred; and supplying water so that
the water content of the waste material is 60.+-.5%.
[0014] The present invention also relates to a process for
producing compost, characterized in that when the compost is
produced by inoculating aerobic composting seed bacteria to an
organic waste material, the process comprises adding sugars to the
waste material in a divisional manner so that the subject of the
fermentation is always conducted through the sugar decomposition
metabolism, that is, before the subject of fermentation is
transferred to the amine/ammonium metabolic system, during an
active fermentation period.
[0015] Further, the present invention is directed to an apparatus
for producing compost, comprising: a fermentation tank having an
oxygen supply means, a water distributing means, and a stirring
means; and means for detecting the water content of an organic
waste material contained in the fermentation vessel and for
controlling, on the basis of the detected result, the amount of
water sprayed (or distributed) by the water distributing means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a side sectional explanatory diagram showing one
embodiment of an apparatus of the present invention.
[0017] FIG. 2 is a plan explanatory diagram showing one embodiment
of the apparatus of the present invention.
[0018] FIG. 3 illustrates the temperature change at the
fermentation in case of composting spent grains.
[0019] FIG. 4 illustrates concentrations of amine and ammonium in
the gaseous phase discharged during fermentation of spent
grains.
[0020] FIG. 5 illustrates concentration of lower fatty acid
contained in the fermented product of the spent grains.
[0021] FIG. 6 illustrates concentration of cellulase activity
during fermentation of the spent grains.
[0022] FIG. 7 illustrates the fermentation period and temperature
during the fermentation in case of composting the spent grains.
[0023] FIG. 8 illustrates a change of a concentration of amines and
ammonium formed during fermentation of the spent grains.
[0024] FIG. 9 illustrates a relation between addition time of sugar
and the change of the fermentation temperature.
[0025] FIG. 10 illustrates ammonium formed during fermentation at
the portions where saccharides are added in a divisional manner and
a batch manner (addition at a time).
[0026] FIG. 11 illustrates the amount of the lower fatty acid
contained in the fermented products at the portions where sugars
are added in a divisional manner and a batch manner.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] In the present invention, an organic waste material means
disposal from food manufacturing factories, food processing
facilities, and the like, including spent grains disposed from beer
factories, fish cake disposed from fishery processing factories,
and other grain lees such as soybean pulp disposed in the course of
bean curd production. These waste materials contain carbohydrate,
protein, fat, and the like, and the water content typically ranges
from 55 to 70% (it is noted that these are moisture-controlled for
the purpose of easy transportation or reuse). When the water
content of the organic waste material as material is beyond this
range, the water content must be adjusted so that the aerobic
fermentation can be effectively conducted.
[0028] Although any saccharides may be added upon the fermentation
of the organic waste material if it can be used for the compost
production by initiated bacteria (seed bacteria), molasses or
blackstrap molasses is preferable. In particular, the blackstrap
molasses are more preferable which are extraction lees obtained
when saccharides is fined and contain molasses.
[0029] As seed bacteria for the compost production, off-the-shelf
compost or commercially available microorganisms can be used.
[0030] A fermentation apparatus as shown in FIGS. 1 and 2 may be
used as an apparatus for producing compost according to the present
invention. The main portion of the apparatus is a fermentation
vessel, and an open fermentation vessel is typically used therefor.
The fermentation vessel includes an oxygen supply means for
constantly keeping the oxygen concentration around the material
during fermentation at a predetermined concentration or more, and a
water distributing means for keeping the water content in the
fermented product of the material during fermentation under the
most appropriate state. It further includes a stirring means for
regularly stirring the whole material during fermentation to
realize uniformity of the aerobic bacteria growth within the
vessel.
[0031] As the temperature rises in the course of compost
production, an evaporation of water from the material cannot be
avoided, and if it is left as it is, the aerobic fermentation may
not be smoothly conducted. Therefore, as previously described,
water is appropriately supplied by the water distributing means.
For this purpose, the water content of the material during
fermentation must be found. Accordingly, the apparatus of the
present invention may include means for detecting the water content
of the material within the fermentation vessel and means for
controlling the amount of water sprayed by the water distributing
means on the basis of the detected result. Alternatively, it may
include an apparatus for controlling the water distributing means
which preliminarily determines the timing of water supply and the
supply amount based on the data of the water content of the
material relative to the temperature and that of the water content
of the material relative to the fermentation duration, both of
which measured at a test operation of the fermentation apparatus to
be provided as apparatus control data, such that the water content
in the material may be adjusted by monitoring and measuring the
temperature of the material during fermentation, or the
fermentation duration, and providing the measured data to the
control apparatus to control the water distributing means.
[0032] FIG. 1 is a side sectional explanatory diagram showing the
compost production apparatus, and FIG. 2 is a plan explanatory
diagram showing said apparatus. In the figures, reference numeral 1
denotes an open fermentation vessel, 2; an aeration pipe, 3; an air
blower, 4; a water distribution pipe, 5; a stirrer, and 6; a
stirring blade. It is noted that although not shown in the
drawings, the apparatus of the present invention also includes a
distribution unit for supplying water to the material during
fermentation through the water distribution pipe 4, a detection
means for detecting the water content in the material, and a
control means for controlling the distribution unit on the basis of
detection data from the above detection means.
[0033] Further, as a process for controlling the distribution unit,
other than the above description, there is also a process for
preliminarily memorizing the apparatus control data indicative of
the timing and the supply amount of supplying water on the basis of
the above-described material temperature or the fermentation
duration, for measuring the material temperature or the
fermentation duration, and for controlling the distribution unit
through the control means based on the above-described memory.
[0034] The present invention will DOW be described with reference
to the figures. First, the material is charged into a fermentation
vessel, and the seed bacteria are then inoculated, so that the
fermentation operation is initiated. The material is entirely
stirred by the rotation of the stirring blade 6 in the stirrer 5
moving reciprocally in a longitudinal direction of the fermentation
vessel 1. The whole material is stirred so that the aerobic
microorganism can grow predominantly and is extended thereover.
Preferably, stirring is conducted twice or more a day in the
fermentation period. This enables uniformity of the growth of the
aerobic microorganism to be realized. Oxygen is introduced from the
air blower 3 so that oxygen (typically, air) can be supplied over
the entire material, and then directed through the aeration pipe 2
to the material. As a result, oxygen is introduced into the
fermentation vessel, so that the oxygen concentration in the
material layer within the fermentation vessel can be kept at 15% or
more, preferably 17 to 21%. Therefore, the entire material can be
fermented under the aerobic condition.
[0035] Further, the water content of the material is measured by a
detection means to adjust the water content of the material during
fermentation. The measurement results are transmitted to the
control means, where the amount of water distributed to the
material is determined to control the amount of water distributed
from the water distribution pipe 4 for adjustment. In this manner,
the water content of the material during fermentation can be kept
at 60.+-.5%. As a result, satisfactry fermentation by the aerobic
microorganism can be maintained. Generally, it takes about 3 to 4
weeks to produce compost.
[0036] Since the material during fermentation gradually becomes
viscous, if it is left as it is, it could be combined with each
other, and oxygen could not be uniformly supplied over the entire
material, possibly resulting in difficulty in continuing the
aerobic fermentation. Therefore, according to the present
invention, the material is stirred to break the solidified product,
and therefore oxygen can be supplied over the entire material.
[0037] In the compost production with the aerobic fermentation,
since the thermophilic fermentation is continued, water may be
drastically vaporized by fermentation heat, possibly resulting in
difficulty in maintaining good fermentation-state. For this reason,
the water content in the material during fermentation is
periodically examined to determine the amount of water to be
distributed based on the detected information, supply water short,
and thereby keep the water content at 60.+-.5% which is the most
appropriate.
[0038] When sugars are added, the addition time is determined using
the fermentation temperature just after the initiation of
fermentation as index of the fermentation state. The activation of
fermentation accompanies heat. The fermentation temperature
drastically rises, the high temperature state maintains for about 1
to 2 weeks, and the primary fermentation is then completed.
Thereafter, for about 2 weeks, the secondary fermentation with
actinomycetes or molds (filamentous fungi) is performed at the
fermentation temperature of almost 20 to 30.degree. C., and
composting terminates throughout the fermentation process for about
30 days.
[0039] In the primary fermentation, it is conceivable that
microorganisms during fermentation repeat in the order of growth,
increment of microorganism, activation, and growth in a cycle. In
the batch addition, the number of fungi increases using sugars as
growth energy, and when sugars are consumed, protein or
hemicellulose is decomposed to generate energy. Therefore, more
amine/ammonium is generated in the metabolic process. In the
divisional addition, however, growth is conducted using sugars as
growth energy, and the fungus body captures protein contained in
the fermented product as a microbial body protein. When sugars are
consumed, the growth is temporarily stopped, thereby to fall the
fermentation temperature. If sugars are added again at this stage,
it is considered that the growth is activated to inhibit yield of
amine/ammonium. This type of fermentation continues until protein
contained in the fermented product is consumed.
[0040] When no elevation of the temperature is observed even if
sugars are added, which is occurred at a period of about 2 weeks,
it means that the primary fermentation is completed, and then the
addition of sugars is stopped at this stage.
[0041] Accordingly, as the fermentation operation continues, the
compost becomes gradually viscous, forming a solidified product by
combining with each other. When stirring further continues, the
compost having a certain dimension and weight, and thus the compost
being excellent in processing can be obtained.
[0042] A case where spent grains are used as the material will now
be described. Most of the obtained compost is in the form of flake,
having grain size of about 5 to 10 mm. Therefore, when the compost
is dispersed, there is no fear that it scurries due to wind or the
like. Incidentally, the cause to increase viscosity of the compost
is believed that hemicellulose or cellulose formed on the surface
is decomposed in the fermentation process to generate sugars.
[0043] The present invention will now be described with reference
to examples, etc., but the present invention is not limited
thereto.
EXAMPLE 1
[0044] About 15 m.sup.3 of spent grains (moisture content of about
67%) yielded in a beer factory were stored in a fermentation vessel
for producing compost. 20 g of this spent grains were suspended to
100 ml of distilated water, while pH of 5.4 was obtained The spent
grains were delivered by about 1 m.sup.3 to a batch fermentation
vessel having the width of 2 meters, the height of 1.2 meters, and
the depth of 13 meters by a bucket loader. Two percent (v/v) of
spent grains compost are added thereto as seed bacteria, these are
mixed, and then the mixture is more sufficiently stirred by a
stirrer, completing preparation for composting.
[0045] As for a fermentation management condition after the
completion of preparation, aeration pipes each having 2 mm in
diameter of apertures spaced by 10 cm were placed on a floor of the
fermentation vessel in parallel at intervals of 60 cm. These pipes
were held by continuous aeration by a forcible air blower, and the
oxygen concentration within the fermentation vessel at this stage
was 15% or more. Water (60.+-.5%) was kept by stirring (twice a
day) by the above-noted stirrer using a water distribution pipe and
by distributing water at the same time.
[0046] After the initiation of preparation, within 2 to 3 days, the
spent grains contained in the fermentation vessel elevated the
temperature, while the maximum temperature during fermentation
reaching 70.degree. C. or more (FIG. 3). As the fermentation
proceeds, gas such as ammonia gas and amine occurred (FIG. 4), and
generation of isobutyric acid, isovaleric acid, acetic acid, and
the like was observed FIG. 5).
[0047] Thereafter, as the fermentation continued while aerating,
ammonia gas, amine gas, lower fatty acid, and the like
substantially disappeared within about 2 weeks (FIG. 4), the
fermentation temperature became 40.degree. C. or less (FIG. 3), and
a stable state as compost was obtained. Thus, after two weeks, the
stirring times were reduced to once a day, while the aeration
continued. Then, it appears the growth of fungi and/or
actinomycetes, the cellulase activity was improved, and
decomposition of refractory substances such as cellulose was
facilitated (FIG. 6).
[0048] Thirty days later from the begining of fermentation, about 7
m.sup.3 of compost was obtained. Most of this compost was in the
form of flake, having the grain size of 5 to 10 mm.
TEST EXAMPLE 1
[0049] Two percent (w/w) of spent grains compost were added to
about 15 m.sup.3 (7.8 tons) of spent grains (adjusted to the
moisture content of 55 -70%) yielded in a beer factory and mixed.
The resulting mixture was delivered to a batch fermentation vessel
having the width of 2 meters, the height of 1.2 meters, and the
depth of 13 meters, so that a preparation for composting was
completed.
[0050] As for a fermentation management condition after the
completion of preparation, aeration pipes (diameter of 5 cm) each
having 2 mm in diameter of apertures spaced by 10 cm were placed on
a floor of the fermentation vessel in parallel at intervals of 60
cm. The aeration into the fermentation vessel through these pipes
was forced. Then, the oxygen concentration within the fermentation
vessel indicated 15% or more. Further, water was kept at 60.+-.5%
using the distribution pipe, and stirring was conducted twice or
more a day by a puddle stirrer so that the fermentation can be
uniformly conducted.
[0051] The fermentation state was examined, the temperature change
at the fermentation at the center portion of the fermentation layer
and in the vicinity of the floor surface were measured, and the
concentration change of amines and ammonium gas was also measured
by a gaseous detection tube to determine the timing of addition of
sugars in a divisional manner. The result was shown in FIGS. 7 and
8.
[0052] As a result, the fermentation temperature of the spent
grains drastically increased from the second day after the
beginning of preparation, 3 to 4 days later reaching about
70.degree. C. which is the maximum temperature during fermentation,
and active fermentation was apparently being conducted. At the same
time, amines and ammonium gases were actively generated, and
therefore, it was discovered that yield was associated with the
temperature at the beginning of fermentation.
EXAMPLE 2
[0053] The aerobic fermentation was conducted using the same
material as that of Test Example 1 in the same manner. That is, the
fermentation was initiated at the stage of the primary
fermentation, and as about 2 to 3 days elapsed, the temperature
increased by heat caused by the fermentation to about
65.+-.10.degree. C. which is the maximum temperature at the
fermentation (FIG. 7). At this stage, 100 kg (corresponding to
about 0.1% of the whole material) of blackstrap molasses
(manufactured by Naka-Nihon Hyouto K. K.) were entirely added to
the material. Concurrently, water was supplied and the material was
stirred. The state of the fermentation temperature at this time was
shown in FIG. 9. FIG. 9 shows detailed change of the fermentation
temperature in the period from the initiation of fermentation till
the fifth day. That is, it shows a partial detail of the
fermentation temperature graph shown in FIG. 7. In the graph shown
in FIG. 9, the fermentation temperature gradually decreased from
the initial third day. It is determined that the fermentation due
to the sugar decomposition metabolism was in the state of being low
due to decrease of the sugar content serving as an energy source.
Then, at the point indicated by an arrow A, 100 kg of blackstrap
molasses were added to the material, whereby it can be clearly
observed from FIG. 9 that the fermentation was activated again.
[0054] Incidentally, the fermentation temperature went down
drastically at the A point, which resulted from the fact that water
was supplied and the material was stirred at the same tine of
addition of blackstrap molasses, as previously described. Further,
the fact that the outside air temperature was below 10.degree. C.
when the experiment was made was one of the factors.
[0055] The drastic change of the fermentation temperature at the B
point after the lapse of 6 to 8 hours from the A point was caused
by stirring of the material (stirred twice a day). Further,
subsequent point of adding blackstrap molasses was implemented at
the point C on the fifth day after the initiation of fermentation.
In a similar manner at the point A, 100 kg of blackstrap molasses
was added, and at the same time, water was supplied and the
material was stirred. From this time, 100 kg of blackstrap molasses
was added every 2 to 3 days (divisional addition portion) until the
primary fermentation period terminated (for about 2 weeks). After
the primary fermentation conducted for about 2 weeks was completed,
the secondary fermentation for about 2 weeks was conducted, and the
fermentation was completed through the whole process of
fermentation for about 30 days.
[0056] The concentrations of ammonia gas and lower fatty acid were
measured in the fermentation period. The results are shown in FIGS.
10 and 11. For the purpose of comparison, an experiment was made
with respect to the batch addition portion in which the blackstrap
molasses were added in a batch manner at the beginning of
fermentation, the result of measurement of which is shown together
therewith. Further, some index for compost components as a basis
for using it as compost was measured in a conventional means.
Incidentally, the non-addition group as a control in which no
blackstrap molasses were added was also measured. The result of
measurement for the respective components are shown in Table 1.
1 TABLE 1 Non- Batch Divisional Addition Addition Addition Portion
Portion Portion (% in anhydride) Ash Content 10.13 10.16 9.63
Organic Material 89.87 89.84 90.37 Whole Nitrogen 5.06 5.33 5.16
Ammonium Nitrogen 0.68 0.53 0.52 Potassium (K.sub.2O) 0.15 0.45
0.54 Phosphorus (P.sub.2O.sub.5) 3.44 3.27 2.44 Moisture Content
(%) 47.60 45.00 38.40 pH 7.27 7.21 6.93 Electrical Conductivity
1890 2450 2420 (mS/cm) Chromaticity (L) 20.45 20.32 21.33
Chromaticity (a) 3.76 3.87 3.50 Chromaticity (b) 6.26 6.04 5.74
[0057] As is apparent from the figures, it is observed that amount
of ammonia gas was inhibited by about 50% in the divisional
addition portion, comparing that of the batch addition portion.
Further, amount of lower fatty acid which has an ability of
inhibiting the growth of plants was also inhibited to half or less
of that of the batch addition portion.
[0058] On the other hand, comparing the compost components, no
remarkable difference was observed in the most indices in the 3
test portions, and therefore no influence to the compost components
due to addition of the blackstrap molasses was observed.
[0059] Industrial Applicability
[0060] According to the present invention, organic waste materials
disposed from food processing factories and the like can be
effectively utilized as the material for producing compost.
Further, since the fermentation is designed to be always conducted
under the aerobic condition, unpleasant odors can be prevented from
occurring in the fermentation period, and the fermentation can be
effectively completed within a short period of time. Still further,
a process and an apparatus is provided for effectively inhibiting
occurrence and accumulation of lower fatty acid serving as a factor
for growth inhibition of plants, and for effectively producing
compost of high quality.
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